Nanotechnology General News

(Nanowerk News) Dolomite has announced that its microfluidic device fabrication expertise is being used by automated laboratory equipment specialist, Syrris Ltd, within its novel range of flow reactor instruments. These microfluidic flow reactor modules supplied by Dolomite, enable the fast and efficient processing of chemicals for test and analysis. Used within Syrris's flow reactor instruments, this technology is starting to have a significant impact on companies involved in such areas as drug discovery, DNA analysis and forensic science, by greatly accelerating their research.

Dolomite is a leader in Microfluidics, also known as ‘lab on a chip'. This is an exciting new field of science and engineering that enables very small-scale fluid control and analysis, allowing instrument manufacturers to develop smaller, more cost-effective and more powerful systems. With lab-on-a-chip technology, entire complex chemical management and analysis systems are created in a microfluidic chip and interfaced with, for example, electronic and optical detection systems.

“Flow chemistry in microreactors often happens much faster than reactions in a bulk vessel, as a result of being able to run at elevated temperature,” said Philip Homewood, Engineering Manager at Dolomite.

“It is also possible to improve product yield because the reaction conditions in a flow microreactor are closer to ideal conditions in terms of temperature and input reagent concentration. This technology is bringing a lot of important new benefits to the life science community and is having a major influence on the future of scientific instrument design and modern chemistry.”

UK company Syrris specialises in flow reactor tools for enhancing the productivity of R&D chemists. Their market-leading product Africa, a modular system for reaction optimisation, reduces the time taken to develop, synthesize, work-up and analyse a chemical entity. In laboratories around the world the Africa system is speeding up the drug discovery process.

“The microfluidic reactor chips from Dolomite are a critical component of the Africa system,” said Mike Hawes, Marketing Manager at Syrris. “Mixing in a batch reactor is quite random whereas in a microfluidic flow reactor it is far more uniform. For some processes like nano-particle manufacturing and crystallisation processes, the nano-particles or crystals end up being much more uniform in comparison to an equivalent batch reactor process. This important benefit, along with the speed and control achievable with this technology, is enabling us to help scientists accelerate their research and achieve more reproducible results.”

Key to the fabrication of these microfluidic devices is the use of microfabrication techniques capable of creating microchannels and complex structures in materials suitable for handling chemicals without being chemically attacked. Dolomite has expertise in the fabrication of devices in one such inert material, glass. “Glass is susceptible to breakage and chipping making it a difficult material to handle,” said Phil Homewood. “This is one of the main reasons why there are so few suppliers of glass microfluidic devices in the world.”

One of the challenges in the design and manufacture of microreactor chips includes getting a sufficient reaction volume. Most chips are less than 100microlitres in volume. To achieve greater volumes, Dolomite etches channels in both glass layers. The micron-sized features on the two patterned layers are aligned, before being bought into optical contact and thermally bonded to create the final device. “Recently we have developed a technique that enables us to align features as small as 5 microns wide”, said Phil Homewood. “Another challenge was the design of the mixing junction to make sure the diffusional mixing was fast enough. This was achieved by having a narrow channel after the mixing junction to keep the diffusion distance low. Also before the mixing junction, one of the input streams was split onto two streams and combined either side of the other input stream. The effect is that the diffusion distance is reduced by a factor of two. This reduces diffusional mixing time by a factor of four. Although each chip is only 28x90mm in size it has between 1.8 - 2.5m of reaction channel.”